Composite textile yarn for use in papermaking felts



May 9, 195o E. H. HALL 2,506,667

COMPOSITE TEXTILE YARN FOR USE IN PAPERMAKING FELTS Filed 'Nov. 24, 1948 Patented May 9, 1950 comosrrs TEXTILE YARN Fon USE 1N rarnamnmo FEI/rs Edward Hall, Fitchburg, Mass. Application November 2.4, 1948, Serial No. 61,765

5 Clflimil.` (Cl. 57-140) This invention pertains to textile yarn for use in the manufacture of paper drying felts or the like and to a novel method of making this yarn.

Paper makers drying felts, when used in the manufacture of kraft papers, fiber board, and similar products, are subjected to very high'temperatures and, if made lof cotton yarn, deteriorate very rapidly. To overcome this dimculty. it has been proposed to make 'such felts of so.- called asbestos yarn. However, since asbestos iiber is not strong enough when used alone to make a yarn acceptable for use in weaving such felts, the yarns actually employed ordinarily are formed by twisting o r plying one or more fine cotton yarns (for example, yarn of the order of from No. 14 to No. 20, cotton count) with an asbestos roving. While felts made from such composite yarns are much longer lived than lthose made from cotton alone, so far as resistance to heat is concerned, they do not have as great initial tensile strength as felts made solely from cotton. As these felts are very wide and heavy and are driven at very high linear velocities, they do not last long, and the expense of replacing them constitutes a substantial item` in paper manufacture.

It has heretofore been proposed to substitute rayon for the cotton in such felts but' as the strength of rayon is very small when wet, it is ofno practical value for this purpose. It has likewise been proposed to employ filament nylon in place of the cotton in the manufacture'of the composite asbestos yarn, but filament nylon has a very smooth slippery surface and when such filament nylon is used as a reinforce for an asbestos roving, the asbestos is scraped oif from the nylon reinforce element during' the passage of the composite yarn through the loom and the asbestos plugs up the loom reed, resulting4 in an imperfect and substantially valueless product.

Nylon has manifest advantages as 'compared with cotton if it could be used as the reinforce element for a composite asbestos yarn, in particular, its great tensile strength and its resistance to heat and to the action of oil and grease.

A principal object of the present invention is to provide a novel composite yarn in which the bulk of the yarn consists of asbestos iiber, but having a reinforce element of nylon, and which is capable of being woven without substantial separation of the asbestos fiber from its reinforce element in the weaving of a paper maker's felt. A further object is to provide a novel method of making such a composite yarn in which nylon constitutes the reinforcing element. Other further objects and advantages of the invention will be pointed out in the following vmore detailed description and Iby reference to the accompanying drawings wherein:

Fig. 1 is a fragmentary elevation, to large scale, of a composite yarn in accordance with one embodiment of the present invention;

Fig. 2 is a transverse section on the line 2-2 of Fig. l:

Fig. 3 is a view similar to Fig. l, illustrating a modification;

Fig. 4 is a section on the line t-l of Fig. 3;

Fig. 5 is a fragmentary elevation, to large scale, diagrammatically illustrating a nylon reinforcing yarn useful in the practice of the present invention;

Fig. 6 is a similar elevation diagrammatically illustrating a nylon yarn of a different type useful in making the composite yarn of the present invention;

Fig. 7 is a fragmentary elevation diagrammaticaily illustrating another form of nylon yarn useful for the purpose; and

Fig. 8 is a fragmentary plan view of a woven paper driers felt in which the improved yarn of the present invention is used as the warp yarn.

Referring to the drawings, the numeral 'I designates a composite yarn made in accordance with one embodiment of the present in'- vention. 'I'his yarn comprises asbestos roving 2 wrapped about a plurality of nylon reinforcing yarns 3, 3a. Two such nylon yarns arehere illustrated but it is contemplated, as within the scope of the invention, that one or any desired number of such reinforce yarns may be used. Ordinarily, the asbestos roving will be of much larger diameter than the reinforce yarns and in the completed composite yarn the asbestos iibers l will constitue the maior and predominating material, the purpose oi the nylon yarns being to add the requiste tensile strength to the asbestos. The asbestos roving may be made in accordance with any usual practice employed for making such roving and this roving is then plied with the nylon yarn. As illustrated in Figs. 3 and 4. two asbestos rovings 2, 2a are twisted together with two nylon yarns I, la. This assembly of the asbestos roving and the nylon yarns may be carried out in any suitable manner. It is contemplated that they may be plied by passing them through an ordinary twisting frame. Although, as just suggested.

`the composite yarn' asbestos roving twisted or `otherwise plied with `the reinforcing yarn or yarns. it is also contemplated that the asbestos ber may otherwise be assembled and associated with the nylon rein- Ii'orcing yarn.

may consist of a preformed In accordance with the present invention, the

together according to customary methods and by `means used, for example, in the spinning of `cotton so as to produce the desired spun yarn.

atoom? stood that any equivalent means. whereby the asbestos liber and nylon are mechanically but firmly united, is to be regarded as coming within the scope of the present invention, as dened in the appended claims. Nylon is at present the material which seems to have the above desirable characteristics in highest degree, but it is contemplated that other long-molecular-chain, filament-forming synthetics, which are found to have the above-described ydesirable characteristics, may be substituted for nylon within the scope of the invention.

It is further suggested that when, as illustrated for example in Fig. 3, more than one of the ne reinforce or core yarns is employed, certain of said reinforce yarns may be of a material which Y is'cheaperv than nylon, for instance, cotton, wool Such a yarn differs from lament nylon in having i a multitude of ber ends 6 projecting from its surface so that microscopically its surface is 1 rough and hairy. lWhen such a spun nylon yarn i is associated withasbestos bers in any of the ways above suggested, the projecting fiber ends 6 of the nylon interengage and frictionally grip the asbestos bers so as tomaintain the initial relation of the various bers of the composite yarn during theweaving operation.

While spun nylon is very desirable and preferable for the purpose, it is contemplated that a nylonyarn having a friction surface provided in other ways may likewise be employed for this which has been treated either mechanically or chemically so as to have a rough surface, for

. example, a surface distinguished by a multitude of pits, or by tiny scale-like projections 9, so

l formed that Vthey do not weaken the lament sub- Y 3 stantially, but neverthelessv effectively change the character of the surface ofl the iilament so that.

it is no longer smooth and slippery but is rough and capable of frictionally gripping the asbestos e fibers with which it is associated.

In Fig. 6 a further form ofnylon yarn is llluS- i l purpose. Thus, for example asdiagrammatically indicated in Fig. 5, the yarn 1 is of iilament nylon trated wherein the yarn'l, which may be of filament nylon or spun nylon, as desired, is nely crinkled so as closely to resemble a natural woolen fiber. This crinkling may be `accomplishedby1 mechanical means or by chemical treatment. and by reason of vthe crinkle or curliness of this yarn,

it grips the asbestos fibers, with which it is associated, so as firmly to bond the asbestos to the nylon reinforce. y In Fig. 8, a small section of woven paper-1 makers felt is illustrated, wherein both warps and wefts are composite yarns such as -above described, the `bulk of the yarn being asbestos nber, and each yarn having one or more reinforce yarns of nylon.

vWhile various ways of providing a iirm anchorage between the asbestos bers and the nylon reinforce have been suggested, it is to be under-f or the like. However, in any event, a sufilcient number of the nylon yarns should be employed to insure the advantages inherent in the use of nylon as a reinforce element as above pointed out.

I claim:

1. A composite textile yarn for use in weaving, comprising a roving of asbestos fiber plied with a reinforcing yarn of nylon, the nylon yarn being so constructed and arranged as to provide anchorage for the constituent fibers of the asbestos roving, thereby substantially to maintain theinitial relation of the roving and yarn during Weaving.

2. A composite textile yarn for use in weaving, comprising a roving of asbestos fiber plied with a reinforcing yarn of spun nylon, the nylon yarn being so constructed and arranged as frictionally to grip the constituent fibers of the asbestos roving.

3. 'A composite textile yarn for use in weaving, comprising a roving of asbestos ber plied with a reinforcing yarn of spun nylon having projecting liber ends which interengage with the asbestos bers of the roving so as to maintain the initial vrelation of the roving and yarn during weaving. 4. A composite textile yarn for use in weaving, comprising a roving of asbestos fiber plied with a reinforcing yarn of nylon, the nylon yarn having a rough surface operative frictionally to engage -the asbestos bers of the roving.

5. v`A composite textile yarnv for use in weaving, comprising a roving of asbestos ber plied with a reinforcing yarn of nylon, the nylon yarn being crinkled, thereby frictionally to grip the asbestos roving so as to maintain the initial relation of the roving and yarn during weaving.

EDWARD H. HALL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,199,400 Geier et al. May '1, 1940 2,306,781 Francis, Jr Dec. 29, 1942 2,313,058 Francis, Jr Mar. 9, 1943 2,350,504 Geier et al June 6. 1944 

